cache

Documentation

Index

• type Cache
• type EvictCallback
• type LRU
  • func NewLRU(maxSize int) *LRU
  • func NewLRUWithOptions(maxSize int, opts *Options) *LRU
  • func (c *LRU) CompareAndSwap(key string, oldValue, newValue interface{}) (itemInCache interface{}, replaced bool)
  • func (c *LRU) Delete(key string)
  • func (c *LRU) Get(key string) interface{}
  • func (c *LRU) Put(key string, value interface{}) interface{}
  • func (c *LRU) Size() int
• type Options

Types

type Cache

type Cache interface {
	Get(key string) interface{}

	Put(key string, value interface{}) interface{}

	Delete(key string)

	Size() int

	CompareAndSwap(key string, old, new interface{}) (interface{}, bool)
}

type EvictCallback

type EvictCallback func(key string, value interface{})

EvictCallback is a type for notifying applications when an item is scheduled for eviction from the Cache.

type LRU

type LRU struct {
	TimeNow func() time.Time
	// contains filtered or unexported fields
}

func NewLRU

func NewLRU(maxSize int) *LRU

func NewLRUWithOptions

func NewLRUWithOptions(maxSize int, opts *Options) *LRU

NewLRUWithOptions creates a new LRU cache with the given options.

func (*LRU) CompareAndSwap

func (c *LRU) CompareAndSwap(key string, oldValue, newValue interface{}) (itemInCache interface{}, replaced bool)

CompareAndSwap puts a new value associated with a given key if existing value matches oldValue. It returns itemInCache as the element in cache after the function is executed and replaced as true if value is replaced, false otherwise.

func (*LRU) Delete

func (c *LRU) Delete(key string)

Delete deletes a key, value pair associated with a key

func (*LRU) Get

func (c *LRU) Get(key string) interface{}

Get retrieves the value stored under the given key

func (*LRU) Put

func (c *LRU) Put(key string, value interface{}) interface{}

Put puts a new value associated with a given key, returning the existing value (if present)

func (*LRU) Size

func (c *LRU) Size() int

Size returns the number of entries currently in the lru, useful if cache is not full

type Options

type Options struct {
	// TTL controls the time-to-live for a given cache entry.  Cache entries that
	// are older than the TTL will not be returned
	TTL time.Duration

	// InitialCapacity controls the initial capacity of the cache
	InitialCapacity int

	// OnEvict is an optional function called when an element is evicted.
	OnEvict EvictCallback

	// TimeNow is used to override the behavior of default time.Now(), e.g. in tests.
	TimeNow func() time.Time
}

Options control the behavior of the cache